Values from 0 to 1 in mecanim animation?

Hello,

I'm kinda new with mecanim and animation tab (trying to learn how to use it) I'm using unity 5 RC2 I need to animate a window(unity GUI Rect Transform) from scale(XY) 0 to 1 so basically opening a window / closing a window.

now I've created a controller created an animation clip from 0:00 to 1:00 set the values at 0:00 to scale = 0 set the values at 1:00 to scale = 1

when I play the animation the scale is not precise 1 but like 0.997. how can I still get this to exact 1? I don't want dirty script fixes that will check if the animation is done and force set it It should be possible with the animation tab but I can't figure out how. I've tried setting it to "Flat" (then it checks free smooth automatically as well)

in the mecanim animator I've set the exit time to 1 and transition to 0 when clicking the button I'm calling a function to play the animation once done I'm transitioning it to Idle state all of the states have write defaults off and speed 1 the clip is also sample 60

Hopefully this is enough information.

So yeah as I said I'm quite new and couldn't find someone with a similar problem, or I searched with the wrong keywords.